11 replies to this topic

[floormanager]

Hello,

I've recently had trouble with a seeping HS2 float chamber gasket.  I replaced the gasket with an official SU gasket but it took a few attempts to seal (new gasket each time).  I'm wondering if the lid has deformed over time, with the areas around the screws bottoming out before sufficient compressing force has been achieved.  Any thoughts?

 

Paul

Edited by floormanager, 29 April 2025 - 08:31 PM.

[DeadSquare]

YES.

 

The alloy is cheap casting rubbish, not even fit for making Dinky cars.

 

To test your hypothesis, use valve grinding paste to treat the lid as though it is a valve by rotating it on the float chamber, to show the high spots.  You might be lucky and grind out the leak.

 

As a bodge, thin smear of bath caulk on both sides of the gasket

[68+86auto]

It's probably been over tightened. They don't need to be very tight. There's no pressure that it needs to hold, it just stops any fuel that splashes around.

[floormanager]

Thank you for your suggestions, I will try and test.  I should imagine they have been overtighted (by me even to stop the bloody leak).  New lids are expensive and I wanted to make sure I was not wasting money unnecessarily.  I like the valve grinding paste idea.

 

Paul

[68+86auto]

Thank you for your suggestions, I will try and test.  I should imagine they have been overtighted (by me even to stop the bloody leak).  New lids are expensive and I wanted to make sure I was not wasting money unnecessarily.  I like the valve grinding paste idea.
 
Paul

You could sand it flat using sandpaper on a piece of glass

[Designer]

Hi,

 

Not teaching to suck eggs I hope but don't forget to check  float gap once sanding/grinding has bee done.

 

Paddy

[floormanager]

Not teaching at all!  A very valid piece of advice.  To be honest, whether I'm over-worrying but I would not mind changing the float lids to the ones with a piped overflow, as I don't want to have petrol spilling out from a stuck needle valve and igniting. 

[SKIDDERWOLF]

Why would the float gap need rechecking?

Hi,

Not teaching to suck eggs I hope but don't forget to check float gap once sanding/grinding has bee done.

Paddy

[Designer]

Hi,

 

My thoughts might be wrong in that if you are reducing the thickness of the fuel bowl top by sanding/grinding the bottom of it is that not the base line for setting the float gap.

You are probably talking a thousand may be less may be more being removed, but that will still mean that the float will be lower in the fuel chamber of the bowl therefore activating the shut off valve sooner.

Therefore less fuel in the carb.

 

 

Paddy

[Ethel]

No,

 

You're gapping the float to the lid. Altering the lid to bowl gap will just make the lid (and float) sit lower. If anything the risk would be the float bottoms out on the bowl, but I doubt it will.

 

I think I'd just stick some engineers blue or marker on it & rub the lid & bowl together over a few degrees about the correct orientation. It'd might just need a bit of a chamfer of the screw holes if over tightening pulled the threads.

 

 

 

 

...If anything needed resetting it'd be the mixture adjustment because the lid being lower would lower the fuel level in the float, that sets the level of the fuel in the jet.

[68+86auto]

Hi,
 
My thoughts might be wrong in that if you are reducing the thickness of the fuel bowl top by sanding/grinding the bottom of it is that not the base line for setting the float gap.
You are probably talking a thousand may be less may be more being removed, but that will still mean that the float will be lower in the fuel chamber of the bowl therefore activating the shut off valve sooner.
Therefore less fuel in the carb.
 
 
Paddy

You are correct. It won't make much difference though. The angle of the road would make more difference.

[Designer]

Hi 68+86auto,

 

That makes very interesting reading I had never given any thought to the angle of the road having any effect.

Thank you.

 

Paddy